libglouglou: traceroute TCP working

3 files changed, 119 insertions, 49 deletions

diff --git a/libglouglou/examples/traceroute.c b/libglouglou/examples/traceroute.c
index d78115b..504b3fc 100644
--- a/libglouglou/examples/traceroute.c
+++ b/libglouglou/examples/traceroute.c
@@ -47,7 +47,7 @@ main(int argc, char *argv[])
 
 	ggtr = ggnet_traceroute_new(_ev_base, get_iface(argv[1]));
 	droppriv("nobody", 1, NULL); /* bad practise, use dedicated user */
-	ggnet_traceroute_trace(ggtr, &ip, TRACEMODE_ICMP,
+	ggnet_traceroute_trace(ggtr, &ip, TRACEMODE_AUTO,
 				_cb_traceroute, NULL, NULL);
 
 	event_base_loopexit(_ev_base, &tv);
@@ -56,7 +56,7 @@ main(int argc, char *argv[])
 	if (_answer) {
 		printf("%s:\n", addr_ntoa(&ip));
 		TAILQ_FOREACH(hop, &_route->hops_list, entry) {
-			printf("%s (%d)\n", addr_ntoa(&hop->ip), hop->delay);
+			printf("%2.2d: %s (%d) [XXX %p]\n", hop->ttl, addr_ntoa(&hop->ip), hop->delay, hop);
 		}
 	} else {
 		printf("no answer\n");
diff --git a/libglouglou/libggnet_traceroute.c b/libglouglou/libggnet_traceroute.c
index 879b96c..6a635d0 100644
--- a/libglouglou/libggnet_traceroute.c
+++ b/libglouglou/libggnet_traceroute.c
@@ -78,6 +78,10 @@ static void _req_free(struct ggnet_traceroute_req *);
 static void _cb_recv(evutil_socket_t, short, void *);
 static void _cb_send(evutil_socket_t, short, void *);
 static void _cb_trace_timeout(evutil_socket_t, short, void *);
+static struct ggnet_traceroute_hop *
+	_hop_ip_id(struct ggnet_traceroute_req *, int);
+static struct ggnet_traceroute_hop *
+	_hop_sport(struct ggnet_traceroute_req *, int);
 static void _timeout_set(struct ggnet_traceroute_req *, int, int);
 static int pcap_dloff(pcap_t *); // XXX move to libggnet_utils ?
 
@@ -167,6 +171,10 @@ ggnet_traceroute_trace(struct ggnet_traceroute *ggtr,
 	}
 	memcpy(&req->srcip, &intf_entry.intf_addr, sizeof(struct addr));
 	req->mode = mode;
+	if (mode == TRACEMODE_ICMP) {
+		printf("ERROR: ICMP trace not supported yet\n");
+		return NULL;
+	}
 	TAILQ_INIT(&req->hops_list);
 
 	req->run.ev_recv = event_new(ggtr->ev_base,
@@ -218,23 +226,19 @@ static void
 _cb_recv(evutil_socket_t fd, short what, void *arg)
 {
 	struct ggnet_traceroute_req *req;
-#if 0
 	struct ggnet_traceroute_hop *hop;
 	struct ggnet_traceroute *ggtr;
 	struct pcap_pkthdr ph;
-	u_char *pread, *tmp;
-	struct ip_hdr  *ip, ip_in;
+	u_char *pread;
+	struct ip_hdr  *ip, *ip_in;
 	struct tcp_hdr *tcp;
 	struct icmp_hdr *icmp;
 	struct addr ip_src;
-	char  *reply = "U!";
-	char  *p;
-#endif
+	char  *p, *flags;
 
 	req = arg;
 	printf("XXX cbggnet_traceroute cb_recv %s -> %s\n",
 			addr_ntoa(&req->srcip), addr_ntoa(&req->target->ip));
-#if 0
 	// XXX call cb_hop if hop successfuly detected
 	// req->cb_hop(req, hop, req->data);
 	req = arg;
@@ -242,29 +246,40 @@ _cb_recv(evutil_socket_t fd, short what, void *arg)
 
 	if ((pread = (u_char *) pcap_next(ggtr->pcap, &ph)) == NULL) {
 		printf("libggnet_traceroute _cb_recv: read error\n");
-		return;
+		goto reschedule_recv;
 	}
 
+	printf("XXX packet received\n");
 	/* decode the current packet : ttl, ip, ... */
-	tmp = pread + ctx->dl_len;
-	ip = (struct ip_hdr *) tmp;
-	if (ip_h->ip_v != 4)
-		return;
-	p = inet_ntoasc(ip_h->ip_src);
+	ip = (struct ip_hdr *) (pread + ggtr->pcap_dllen);
+	if (ip->ip_v != 4)
+		goto reschedule_recv;
+	p = ip_ntoa(&ip->ip_src);
 	if ((addr_aton(p, &ip_src)) == -1)
-		return;
+		goto reschedule_recv;
+	printf("XXX packet IP received from %s, ip_id %d\n", addr_ntoa(&ip_src), ntohs(ip->ip_id));
 
-	switch(ip_h->ip_p) {
+	switch(ip->ip_p) {
 
 		case IP_PROTO_TCP:
-			/* should be our target */
 			if (addr_cmp(&ip_src, &(req->target->ip)) != 0) 
-				return;
-			tcp = (struct tcp_hdr *)(ip + IP_HDR_LEN);
+				goto reschedule_recv;
+			tcp = (struct tcp_hdr *)((u_char *)ip + IP_HDR_LEN);
+			printf("XXX TCP %d %d %d\n", ntohs(tcp->th_sport),
+				req->params.tcp.dport, tcp->th_seq);
 			if (((tcp->th_flags == TH_SYN + TH_ACK) || 
-						(tcp->th_flags == TH_RST + TH_ACK)) &&
-					(htons(tcp->th_sport) == ctx->dport))  {
-				hop = req->target;
+					(tcp->th_flags == TH_RST + TH_ACK)) &&
+					(ntohs(tcp->th_sport) == req->params.tcp.dport))  {
+				/* target answer */
+				printf("XXX found target !\n");
+				hop = _hop_sport(req, ntohs(tcp->th_dport));
+				if (!hop) {
+					printf("libggnet_traceroute _cb_recv: WARNING: TCP answer with dport not matching sent sport (%d) not found !\n",
+						ntohs(tcp->th_dport));
+					goto reschedule_recv;
+				}
+
+				memcpy(&hop->ip, &ip_src, sizeof(struct addr));
 				hop->answer_count++;
 				flags = "SA";
 				if (tcp->th_flags == TH_RST + TH_ACK)
@@ -275,17 +290,19 @@ _cb_recv(evutil_socket_t fd, short what, void *arg)
 			break;
 
 		case IP_PROTO_ICMP:
+			printf("XXX is ICMP\n");
 			/* answer from a hop */
-			icmp = (struct icmp_hdr *)(ip + IP_HDR_LEN);
+			icmp = (struct icmp_hdr *)((u_char *)ip + IP_HDR_LEN);
 			/* XXX ? look for TTL_EXPIRED, PROHIBITED msgs */
-			ip_in = (struct iphdr *) (ip + sizeof(struct iphdr) +
-					sizeof(struct icmphdr));
-			hop = _hop_ttl(req, ip_in->ttl);
+			ip_in = (struct ip_hdr *)
+				((u_char *)ip + IP_HDR_LEN + ICMP_LEN_MIN);
+			hop = _hop_ip_id(req, ntohs(ip_in->ip_id));
 			if (!hop) {
-				printf("libggnet_traceroute _cb_recv: WARNING: hop ttl %d not found !",
-						ip_in->ttl);
-				return;
+				printf("libggnet_traceroute _cb_recv: WARNING: ICMP answer with IP ID not matching sent IP ID (%x) not found !\n",
+						ntohs(ip_in->ip_id));
+				goto reschedule_recv;
 			}
+			memcpy(&hop->ip, &ip_src, sizeof(struct addr));
 			hop->answer_count++;
 			if (icmp->icmp_type == ICMP_UNREACH) {
 				switch (icmp->icmp_code) {
@@ -305,16 +322,17 @@ _cb_recv(evutil_socket_t fd, short what, void *arg)
 				}
 			} else if (icmp->icmp_type == ICMP_TIMEXCEED) {
 				strncpy(hop->answer, "A!", sizeof(hop->answer));
-				reply = "X!";
-				event_add(&ctx->send_ev, &ctx->tv);
 			}
-			ctx->hop++;
+			if (hop->ttl == req->run.last_ttl_sent &&
+					addr_cmp(&hop->ip, &req->target->ip)) {
+				/* send more probes */
+				event_add(req->run.ev_send, NULL);
+			}
 			break;
 	}
-	fflush(stdout);
 
-	/* do we need to send more packets ? */
-#endif // if 0
+reschedule_recv:
+	event_add(req->run.ev_recv, NULL);
 }
 
 static void
@@ -325,7 +343,7 @@ _cb_send(evutil_socket_t fd, short what, void *arg)
 	struct ggnet_traceroute *ggtr;
 	u_char buf[BUFSIZ];
 	struct trace_pkt *pkt;
-	int len, lensent, ttl, i;
+	int len, lensent, ttl, ip_id, sport, i;
 
 	req = arg;
 	printf("XXX cbggnet_traceroute cb_send %s -> %s\n",
@@ -342,36 +360,42 @@ _cb_send(evutil_socket_t fd, short what, void *arg)
 		}
 		hop->ttl = ttl;
 		//addr_pack(hop->ip, ADDR_TYPE_IP, IP_ADDR_BITS, ip, IP_ADDR_LEN);
+		ip_id = rand_uint16(ggtr->pkt_rand);
+		sport = rand_uint16(ggtr->pkt_rand);
 		switch (req->mode) {
 		case TRACEMODE_AUTO:
 		case TRACEMODE_TCP:
+			req->params.tcp.dport = TRACE_DPORT;
 			ip_pack_hdr(&pkt->pkt_hdr_i.ip, IP_TOS_LOWDELAY, len,
-				rand_uint16(ggtr->pkt_rand), 0, ttl,
-				IP_PROTO_TCP, 
+				ip_id, 0, ttl, IP_PROTO_TCP, 
 				req->srcip.addr_ip, req->target->ip.addr_ip);
 			tcp_pack_hdr(&pkt->pkt_hdr_t.tcp,
-				rand_uint16(ggtr->pkt_rand), TRACE_DPORT, 
+				sport, req->params.tcp.dport, 
 				rand_uint32(ggtr->pkt_rand), 0, 
 				TH_SYN, rand_uint16(ggtr->pkt_rand), 0);
+			break;
 		case TRACEMODE_ICMP:
 			ip_pack_hdr(&pkt->pkt_hdr_i.ip, IP_TOS_LOWDELAY, len,
-				rand_uint16(ggtr->pkt_rand), 0, ttl,
-				IP_PROTO_ICMP, 
+				ip_id, 0, ttl, IP_PROTO_ICMP, 
 				req->srcip.addr_ip, req->target->ip.addr_ip);
 			icmp_pack_hdr(&pkt->pkt_hdr_t.icmp, ICMP_ECHO, 8);
+			break;
 		}
 		ip_checksum(pkt, len);
 		TAILQ_INSERT_TAIL(&req->hops_list, hop, entry);
-		for (i=0; i<TRACEROUTE_NB_PROBES; i++)
+		for (i=0; i<TRACEROUTE_NB_PROBES; i++) {
+			hop->ip_ids[i] = ip_id;
+			hop->sports[i] = sport;
 			lensent = ip_send(ggtr->pkt_ip, pkt, len);
 			if (len < 0)
 				warn("_cb_send : ip_send error");
 			if (lensent < len)
 				warn("_cb_send : ip_send short send (%d < %d",
 						lensent, len);
-		_timeout_set(req, TIMEOUT_TOTAL_S, 0);
+		}
 	}
 	req->run.last_ttl_sent = ttl;
+	_timeout_set(req, TIMEOUT_TOTAL_S, 0);
 }
 
 static void
@@ -384,17 +408,55 @@ _timeout_set(struct ggnet_traceroute_req *req, int sec, int usec)
 }
 
 static struct ggnet_traceroute_hop *
-_hop_last(struct ggnet_traceroute_req *req)
+_hop_ip_id(struct ggnet_traceroute_req *req, int ip_id)
+{
+	struct ggnet_traceroute_hop *h;
+	int i;
+
+	TAILQ_FOREACH_REVERSE(h, &req->hops_list, tailhead, entry) {
+		for (i = 0; i<TRACEROUTE_NB_PROBES; i++)
+			if (h->ip_ids[i] == ip_id)
+				return h;
+	}
+	return NULL;
+}
+
+static struct ggnet_traceroute_hop *
+_hop_sport(struct ggnet_traceroute_req *req, int sport)
 {
 	struct ggnet_traceroute_hop *h;
+	int i;
 
 	TAILQ_FOREACH_REVERSE(h, &req->hops_list, tailhead, entry) {
-		if (h->answer_count > 0)
-			return h;
+		for (i = 0; i<TRACEROUTE_NB_PROBES; i++)
+			if (h->sports[i] == sport)
+				return h;
 	}
 	return NULL;
 }
 
+/**
+ * Returns the target hop, and clean the hops_list before calling user callback
+ */
+static struct ggnet_traceroute_hop *
+_hop_last(struct ggnet_traceroute_req *req)
+{
+	struct ggnet_traceroute_hop *h, *ht;
+	struct ggnet_traceroute_hop *last = NULL;
+	int found = 0;
+
+	TAILQ_FOREACH_SAFE(h, &req->hops_list, entry, ht) {
+		if (found)
+			TAILQ_REMOVE(&req->hops_list, h, entry);
+		else if (addr_cmp(&h->ip, &req->target->ip) == 0) {
+			last = h;
+			found = 1;
+		}
+	}
+
+	return last;
+}
+
 static void
 _cb_trace_timeout(evutil_socket_t fd, short what, void *arg)
 {
@@ -406,6 +468,7 @@ _cb_trace_timeout(evutil_socket_t fd, short what, void *arg)
 	printf("XXX cbggnet_traceroute cb_trace_timeout (%s -> %s)\n",
 			addr_ntoa(&req->srcip), addr_ntoa(&req->target->ip));
 	last = _hop_last(req);
+	printf("XXX last %p\n", last);
 	if (last)
 		req->target->ttl = last->ttl + 1;
 	req->cb_done(req, req->data);
diff --git a/libglouglou/libggnet_traceroute.h b/libglouglou/libggnet_traceroute.h
index e14cea7..9cd64ad 100644
--- a/libglouglou/libggnet_traceroute.h
+++ b/libglouglou/libggnet_traceroute.h
@@ -21,6 +21,8 @@ struct ggnet_traceroute_hop {
 	int	ttl;
 	int	answer_count; /* on TRACEROUTE_NB_PROBES sent probes */
 	char	answer[2 * TRACEROUTE_NB_PROBES];
+	int	ip_ids[TRACEROUTE_NB_PROBES];
+	int	sports[TRACEROUTE_NB_PROBES];
 	struct addr ip;
 	int	delay;
 	int	delay_dev;
@@ -34,8 +36,13 @@ struct ggnet_traceroute_req {
 	struct ggnet_traceroute_hop *target;
 	struct addr srcip;
 	enum tracemode mode;
-	int	probes_count;
-	int	hops_count;
+	union {
+		struct {
+			int dport;
+		} tcp;
+		struct icmp {
+		} icmp;
+	} params;
 	TAILQ_HEAD(tailhead, ggnet_traceroute_hop) hops_list;
 	struct {
 		struct event *ev_recv;